Pygmy marmoset
The world's smallest true monkey, a gum-feeding specialist of the Amazon.
The pygmy marmoset (genus Cebuella) is a small New World monkey and the smallest true monkey in the world, with an average adult body weight just over 100 g (3.5 oz). Native to rainforests of the western Amazon Basin in South America, it is a gum-feeding specialist, or gummivore, and is found in evergreen and river-edge forests. The genus consists of two species: the Western pygmy marmoset (Cebuella pygmaea) and the Eastern pygmy marmoset (Cebuella niveiventris).
- Common name
- Pygmy marmoset
- Genus
- Cebuella
- Species
- Cebuella pygmaea and Cebuella niveiventris
- Average adult weight
- Just over 100 g (3.5 oz)
- Head-body length
- 117 to 152 mm (4.6 to 6.0 in)
- Tail length
- 172 to 229 mm (6.8 to 9.0 in)
- Native region
- Western Amazon Basin (Brazil, Colombia, Ecuador, Peru, Bolivia)
Lore & Background
Pygmy marmosets live in stable troops of two to nine individuals, typically including a dominant male, a breeding female, and up to four successive litters of offspring. The modal troop size is six individuals. Communication within the group involves a complex system of vocal, chemical, and visual signals, with three main calling signals depending on distance. Chemical signaling from chest and genital glands allows the female to indicate reproductive readiness. The female gives birth to twins twice a year, and parental care is shared among the group.
Reader's Guide
The pygmy marmoset is significant as the smallest true monkey, with a highly specialized diet of tree gum that has driven adaptations such as claw-like nails (tegulae) for clinging, specialized incisors for gouging bark, and an enlarged cecum for digesting gum. Its evolution involved a high rate of body-mass reduction, likely through progenesis. Debate among primatologists over its genus placement has been resolved by maintaining the separate genus Cebuella within the family Callitrichidae, justified by the separation of related species groups into different genera. The species are distinguished primarily by geographical barriers, such as large rivers, with few morphological differences. Their biggest threats are habitat loss and the pet trade.
Did You Know?
- Pygmy marmosets can rotate their heads 180 degrees and leap up to 5 m (16 ft) between branches.
- About 83% of the population lives in stable troops of two to nine individuals, with a modal size of six.
- They use chemical signals from chest and genital glands to communicate reproductive status.
- Their specialized diet of tree gum requires them to gouge bark with incisors and lap up sap with their tongues.
Frequently Asked Questions
What is the Pygmy marmoset?
The Pygmy marmoset is a tiny New World monkey in the genus Cebuella, holding the distinction of being the smallest true monkey on Earth. Adults weigh only a hair over 100 grams, making them extraordinarily compact for primates.
How big is a Pygmy marmoset?
An adult's head-to-body length falls between roughly 117 and 152 millimeters, with the tail adding another 172 to 229 millimeters. At just over 3.5 ounces, it remains the lightest monkey species known.
Where is the Pygmy marmoset found?
Both species are native to the rainforests of the western Amazon Basin in South America. They prefer evergreen stands and the forested edges of rivers within that region.
What does the Pygmy marmoset eat?
It is a dedicated gummivore, relying primarily on tree sap and gum as its staple food source. This specialized feeding strategy distinguishes it from most other small Amazonian primates.
How many species of Pygmy marmoset are there?
The genus Cebuella includes two recognized species: the Western pygmy marmoset (C. pygmaea) and the Eastern pygmy marmoset (C. niveiventris). They are separated mainly by their geographic range across the Amazon Basin.
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